What is the percent composition by mass of hydrogen in H20?

Working with si (metric) units for each of the following commonly used measurements, indicate its symbol. liter gram milliliter kilogram meter centigram milligram centimeter kilometer second millimeter milliseconds

Agas is contained in a thick walled balloon when the pressure changes from 1.21 atm to 2.52 the volume changes from 3.75 l to 1.72 l and the temperature change from 293k to blank k

Asap! will give brainiest when a heat wave strikes a region causing more people to run air-conditioning units, electrical demand increases. what needs to be done to meet this increased demand? raising the control rodslowering the control rodsremoving the control rods